hi guys I want to know the cost of various arduino boards. can you guys help me with this???

Well there are many different vendors that sell both Arduino and Arduino clone boards retail, and as such they can choose how much to charge for their offerings. Perhaps if you tell us what country you are in someone can recommend a in-country seller for you?

Note, unless you are already working with a different microprocessor or board level electronics, the cost of an Arduino itself is only part of the cost. To get started, you should think of getting one of the add-on starter kits that provide lots of the things you will need initially. To some extent, this depends on what you are interested in doing with the Arduino. You don't have to buy everything at once, but it is helpful to have something that you can do when you get the Arduino.

There is an official Arduino starter kit, but it is in short supply, and I think it is expensive enough that most of us would have to think twice about getting it. On the other hand, it looks like well documented (it comes with a book and all of the parts are clearly labeled). I bought an intermediate kit from a US based ebay seller for about $75, and it had an official Uno, breadboard, lots of wires, various sensors, etc. Unfortunately, what it didn't have was documentation, and they just threw all of the components in a few unlabeled plastic bags. In fact, there were several sensors that I didn't know what they were initially, and 6 months later I had need of a force sensor, and discovered it was one of the things in the bag that I had just put aside.

Then there is the issue of branded Arduino or clone. The branded Arduinos are the only ones that the Arduino team makes money off of, and the money obviously pays the staff to come up with new Arduinos. Clones can be much cheaper or come in different packages, but depending on where you get the clones they might have cut corners somewhere.

So lets see what some of my favorite vendors have:

Arduino-info.com -- $40.50 (US) + s/h for an Uno + shield + basic kit. I like arduino-info because one of the owners (Terry King) posts frequently with helpful information on this site. Note, shipping is from China. My order was something like 1-2 weeks (and Christmas may slow things down for china deliveries in general, unless you live near China) http://arduino-direct.com/sunshop/index.php?l=product_detail&p=302

Adafruit.com -- $65.00 (US) + s/h for an Uno + sheild + basic kit. While I like Adafruit for a wide variety of components, I tend to think their kit isn't as user friendly to the novice, since it requires soldering the pins to the board, and if you don't have a soldering gun, that is an extra expense. When I was starting out, I couldn't solder, and I tended to go to places that provided all of the components assembled or at least did not require soldering. Adafruit is based in New York, and has fairly fast shipping to the US: http://www.adafruit.com/products/68

DX's shipping times were (that's past tense) long, a half year to two months ago.Back then waiting for a month after being notified the package was shipped was normal.I ordered a few items recently (5 times since november 23), took DX about a week to prepare shipping and less than 10 days to arrive at my home (in Europe) after that.To me that's very reasonable.I have been ordering about 15 times over the past 3 years, and apart from the long waiting times the past months, i'm satisfied with all i got from them.